[thirdparty/bird.git] / proto / ospf / hello.c

/*
 *	BIRD -- OSPF
 *
 *	(c) 1999--2004 Ondrej Filip <feela@network.cz>
 *	(c) 2009--2014 Ondrej Zajicek <santiago@crfreenet.org>
 *	(c) 2009--2014 CZ.NIC z.s.p.o.
 *
 *	Can be freely distributed and used under the terms of the GNU GPL.
 */

#include "ospf.h"


struct ospf_hello2_packet
{
  struct ospf_packet hdr;
  union ospf_auth2 auth;

  u32 netmask;
  u16 helloint;
  u8 options;
  u8 priority;
  u32 deadint;
  u32 dr;
  u32 bdr;

  u32 neighbors[];
};

struct ospf_hello3_packet
{
  struct ospf_packet hdr;

  u32 iface_id;
  u32 options;
  u16 helloint;
  u16 deadint;
  u32 dr;
  u32 bdr;

  u32 neighbors[];
};


uint
ospf_hello3_options(struct ospf_packet *pkt)
{
  struct ospf_hello3_packet *ps = (void *) pkt;
  return ntohl(ps->options) & 0x00FFFFFF;
}

void
ospf_send_hello(struct ospf_iface *ifa, int kind, struct ospf_neighbor *dirn)
{
  struct ospf_proto *p = ifa->oa->po;
  struct ospf_packet *pkt;
  struct ospf_neighbor *neigh, *n1;
  struct nbma_node *nb;
  u32 *neighbors;
  uint length;
  int i, max;

  if (ifa->state <= OSPF_IS_LOOP)
    return;

  if (ifa->stub)
    return;


  pkt = ospf_tx_buffer(ifa);
  ospf_pkt_fill_hdr(ifa, pkt, HELLO_P);

  if (ospf_is_v2(p))
  {
    struct ospf_hello2_packet *ps = (void *) pkt;

    if ((ifa->type == OSPF_IT_VLINK) ||
	((ifa->type == OSPF_IT_PTP) && !ifa->ptp_netmask))
      ps->netmask = 0;
    else
      ps->netmask = htonl(u32_mkmask(ifa->addr->prefix.pxlen));

    ps->helloint = ntohs(ifa->helloint);
    ps->options = ifa->oa->options & HELLO2_OPT_MASK;
    ps->priority = ifa->priority;
    ps->deadint = htonl(ifa->deadint);
    ps->dr = htonl(ipa_to_u32(ifa->drip));
    ps->bdr = htonl(ipa_to_u32(ifa->bdrip));

    length = sizeof(struct ospf_hello2_packet);
    neighbors = ps->neighbors;
  }
  else
  {
    struct ospf_hello3_packet *ps = (void *) pkt;
    u32 options = ifa->oa->options | (ifa->autype == OSPF_AUTH_CRYPT ? OPT_AT : 0);

    ps->iface_id = htonl(ifa->iface_id);
    ps->options = ntohl((options & HELLO3_OPT_MASK) | (ifa->priority << 24));
    ps->helloint = ntohs(ifa->helloint);
    ps->deadint = htons(ifa->deadint);
    ps->dr = htonl(ifa->drid);
    ps->bdr = htonl(ifa->bdrid);

    length = sizeof(struct ospf_hello3_packet);
    neighbors = ps->neighbors;
  }

  i = 0;
  max = (ospf_pkt_maxsize(ifa) - length) / sizeof(u32);

  /* Fill all neighbors */
  if (kind != OHS_SHUTDOWN)
  {
    WALK_LIST(neigh, ifa->neigh_list)
    {
      if (i == max)
      {
	log(L_WARN "%s: Too many neighbors on %s", p->p.name, ifa->ifname);
	break;
      }
      neighbors[i] = htonl(neigh->rid);
      i++;
    }
  }

  length += i * sizeof(u32);
  pkt->length = htons(length);

  OSPF_TRACE(D_PACKETS, "HELLO packet sent via %s", ifa->ifname);

  switch(ifa->type)
  {
  case OSPF_IT_BCAST:
  case OSPF_IT_PTP:
    ospf_send_to_all(ifa);
    break;

  case OSPF_IT_NBMA:
    if (dirn)		/* Response to received hello */
    {
      ospf_send_to(ifa, dirn->ip);
      break;
    }

    int to_all = ifa->state > OSPF_IS_DROTHER;
    int me_elig = ifa->priority > 0;

    if (kind == OHS_POLL)	/* Poll timer */
    {
      WALK_LIST(nb, ifa->nbma_list)
	if (!nb->found && (to_all || (me_elig && nb->eligible)))
	  ospf_send_to(ifa, nb->ip);
    }
    else			/* Hello timer */
    {
      WALK_LIST(n1, ifa->neigh_list)
	if (to_all || (me_elig && (n1->priority > 0)) ||
	    (n1->rid == ifa->drid) || (n1->rid == ifa->bdrid))
	  ospf_send_to(ifa, n1->ip);
    }
    break;

  case OSPF_IT_PTMP:
    WALK_LIST(n1, ifa->neigh_list)
      ospf_send_to(ifa, n1->ip);

    WALK_LIST(nb, ifa->nbma_list)
      if (!nb->found)
	ospf_send_to(ifa, nb->ip);

    /* If there is no other target, we also send HELLO packet to the other end */
    if (ipa_nonzero(ifa->addr->opposite) && !ifa->strictnbma &&
	EMPTY_LIST(ifa->neigh_list) && EMPTY_LIST(ifa->nbma_list))
      ospf_send_to(ifa, ifa->addr->opposite);
    break;

  case OSPF_IT_VLINK:
    ospf_send_to(ifa, ifa->vip);
    break;

  default:
    bug("Bug in ospf_send_hello()");
  }
}


void
ospf_receive_hello(struct ospf_packet *pkt, struct ospf_iface *ifa,
		   struct ospf_neighbor *n, ip_addr faddr)
{
  struct ospf_proto *p = ifa->oa->po;
  const char *err_dsc = NULL;
  u32 rcv_iface_id, rcv_helloint, rcv_deadint, rcv_dr, rcv_bdr;
  uint rcv_options, rcv_priority;
  uint loc_options = ifa->oa->options;
  u32 *neighbors;
  u32 neigh_count;
  uint plen, i, err_val = 0;

  /* RFC 2328 10.5 */

  /*
   * We may not yet have the associate neighbor, so we use Router ID from the
   * packet instead of one from the neighbor structure for log messages.
   */
  u32 rcv_rid = ntohl(pkt->routerid);
  OSPF_TRACE(D_PACKETS, "HELLO packet received from nbr %R on %s", rcv_rid, ifa->ifname);

  plen = ntohs(pkt->length);

  if (ospf_is_v2(p))
  {
    struct ospf_hello2_packet *ps = (void *) pkt;

    if (plen < sizeof(struct ospf_hello2_packet))
      DROP("too short", plen);

    rcv_iface_id = 0;
    rcv_helloint = ntohs(ps->helloint);
    rcv_deadint = ntohl(ps->deadint);
    rcv_dr = ntohl(ps->dr);
    rcv_bdr = ntohl(ps->bdr);
    rcv_options = ps->options;
    rcv_priority = ps->priority;

    int pxlen = u32_masklen(ntohl(ps->netmask));
    if (pxlen < 0)
      DROP("prefix garbled", ntohl(ps->netmask));

    if ((ifa->type != OSPF_IT_VLINK) &&
	(ifa->type != OSPF_IT_PTP) &&
	((uint) pxlen != ifa->addr->prefix.pxlen))
      DROP("prefix length mismatch", pxlen);

    neighbors = ps->neighbors;
    neigh_count = (plen - sizeof(struct ospf_hello2_packet)) / sizeof(u32);
  }
  else /* OSPFv3 */
  {
    struct ospf_hello3_packet *ps = (void *) pkt;

    if (plen < sizeof(struct ospf_hello3_packet))
      DROP("too short", plen);

    rcv_iface_id = ntohl(ps->iface_id);
    rcv_helloint = ntohs(ps->helloint);
    rcv_deadint = ntohs(ps->deadint);
    rcv_dr = ntohl(ps->dr);
    rcv_bdr = ntohl(ps->bdr);
    rcv_options = ntohl(ps->options) & 0x00FFFFFF;
    rcv_priority = ntohl(ps->options) >> 24;

    neighbors = ps->neighbors;
    neigh_count = (plen - sizeof(struct ospf_hello3_packet)) / sizeof(u32);
  }

  if (rcv_helloint != ifa->helloint)
    DROP("hello interval mismatch", rcv_helloint);

  if (rcv_deadint != ifa->deadint)
    DROP("dead interval mismatch", rcv_deadint);

  /* Check whether bits E, N match */
  if ((rcv_options ^ loc_options) & (OPT_E | OPT_N))
    DROP("area type mismatch", rcv_options);

  /* RFC 5838 2.4 - AF-bit check unless on IPv6 unicast */
  if ((loc_options & OPT_AF) && !(loc_options & OPT_V6) && !(rcv_options & OPT_AF))
    DROP("AF-bit mismatch", rcv_options);

  /* Check consistency of existing neighbor entry */
  if (n)
  {
    uint t = ifa->type;
    if (ospf_is_v2(p) && ((t == OSPF_IT_BCAST) || (t == OSPF_IT_NBMA) || (t == OSPF_IT_PTMP)))
    {
      /* Neighbor identified by IP address; Router ID may change */
      if (n->rid != rcv_rid)
      {
	OSPF_TRACE(D_EVENTS, "Neighbor %R on %s changed Router ID to %R",
		   n->rid, ifa->ifname, rcv_rid);
	ospf_neigh_sm(n, INM_KILLNBR);
	n = NULL;
      }
    }
    else /* OSPFv3 or OSPFv2/PtP */
    {
      /* Neighbor identified by Router ID; IP address may change */
      if (!ipa_equal(faddr, n->ip))
      {
	OSPF_TRACE(D_EVENTS, "Neighbor %R on %s changed IP address to %I",
		   n->rid, ifa->ifname, faddr);
	n->ip = faddr;
      }
    }
  }

  if (!n)
  {
    if ((ifa->type == OSPF_IT_NBMA) || (ifa->type == OSPF_IT_PTMP))
    {
      struct nbma_node *nn = find_nbma_node(ifa, faddr);

      if (!nn && ifa->strictnbma)
	DROP1("new neighbor denied");

      if (nn && (ifa->type == OSPF_IT_NBMA) &&
	  (((rcv_priority == 0) && nn->eligible) ||
	   ((rcv_priority > 0) && !nn->eligible)))
	DROP("eligibility mismatch", rcv_priority);

      if (nn)
	nn->found = 1;
    }

    OSPF_TRACE(D_EVENTS, "New neighbor %R on %s, IP address %I",
	       rcv_rid, ifa->ifname, faddr);

    n = ospf_neighbor_new(ifa);

    n->rid = rcv_rid;
    n->ip = faddr;
    n->dr = rcv_dr;
    n->bdr = rcv_bdr;
    n->priority = rcv_priority;
    n->iface_id = rcv_iface_id;

    if (n->ifa->cf->bfd)
      ospf_neigh_update_bfd(n, n->ifa->bfd);
  }

  u32 n_id = ospf_is_v2(p) ? ipa_to_u32(n->ip) : n->rid;

  u32 old_dr = n->dr;
  u32 old_bdr = n->bdr;
  u32 old_priority = n->priority;
  u32 old_iface_id = n->iface_id;

  n->dr = rcv_dr;
  n->bdr = rcv_bdr;
  n->priority = rcv_priority;
  n->iface_id = rcv_iface_id;

  /* Update inactivity timer */
  ospf_neigh_sm(n, INM_HELLOREC);

  /* RFC 2328 9.5.1 - non-eligible routers reply to hello on NBMA nets */
  if (ifa->type == OSPF_IT_NBMA)
    if ((ifa->priority == 0) && (n->priority > 0))
      ospf_send_hello(n->ifa, OHS_HELLO, n);


  /* Examine list of neighbors */
  for (i = 0; i < neigh_count; i++)
    if (neighbors[i] == htonl(p->router_id))
      goto found_self;

  ospf_neigh_sm(n, INM_1WAYREC);
  return;

found_self:
  ospf_neigh_sm(n, INM_2WAYREC);


  if (n->iface_id != old_iface_id)
  {
    /* If neighbor is DR, also update cached DR interface ID */
    if (ifa->drid == n->rid)
      ifa->dr_iface_id = n->iface_id;

    /* RFC 5340 4.4.3 Event 4 - change of neighbor's interface ID */
    ospf_notify_rt_lsa(ifa->oa);

    /* Missed in RFC 5340 4.4.3 Event 4 - (Px-)Net-LSA uses iface_id to ref Link-LSAs */
    ospf_notify_net_lsa(ifa);
  }

  if (ifa->state == OSPF_IS_WAITING)
  {
    /* Neighbor is declaring itself DR (and there is no BDR) or as BDR */
    if (((n->dr == n_id) && (n->bdr == 0)) || (n->bdr == n_id))
      ospf_iface_sm(ifa, ISM_BACKS);
  }
  else if (ifa->state >= OSPF_IS_DROTHER)
  {
    /* Neighbor changed priority or started/stopped declaring itself as DR/BDR */
    if ((n->priority != old_priority) ||
	((n->dr == n_id) && (old_dr != n_id)) ||
	((n->dr != n_id) && (old_dr == n_id)) ||
	((n->bdr == n_id) && (old_bdr != n_id)) ||
	((n->bdr != n_id) && (old_bdr == n_id)))
      ospf_iface_sm(ifa, ISM_NEICH);
  }

  return;

drop:
  LOG_PKT("Bad HELLO packet from nbr %R on %s - %s (%u)",
	  rcv_rid, ifa->ifname, err_dsc, err_val);
}
Commit	Line	Data
4364b47e OF	1	/*
	2	* BIRD -- OSPF
	3	*
bc4ea680	4	* (c) 1999--2004 Ondrej Filip <feela@network.cz>
70945cb6 OZ	5	* (c) 2009--2014 Ondrej Zajicek <santiago@crfreenet.org>
70945cb6 OZ	6	* (c) 2009--2014 CZ.NIC z.s.p.o.
4364b47e OF	7	*
	8	* Can be freely distributed and used under the terms of the GNU GPL.
	9	*/
	10
	11	#include "ospf.h"
	12
c3226991	13
70945cb6	14	struct ospf_hello2_packet
c3226991	15	{
70945cb6	16	struct ospf_packet hdr;
4727d1db	17	union ospf_auth2 auth;
70945cb6 OZ	18
70945cb6 OZ	19	u32 netmask;
c3226991 OZ	20	u16 helloint;
	21	u8 options;
	22	u8 priority;
	23	u32 deadint;
	24	u32 dr;
	25	u32 bdr;
c3226991	26
70945cb6 OZ	27	u32 neighbors[];
70945cb6 OZ	28	};
c3226991	29
70945cb6	30	struct ospf_hello3_packet
c3226991	31	{
70945cb6 OZ	32	struct ospf_packet hdr;
70945cb6 OZ	33
c3226991	34	u32 iface_id;
d3f4f92b	35	u32 options;
c3226991 OZ	36	u16 helloint;
	37	u16 deadint;
	38	u32 dr;
	39	u32 bdr;
c3226991	40
70945cb6 OZ	41	u32 neighbors[];
70945cb6 OZ	42	};
b29c620f	43
4364b47e	44
4727d1db OZ	45	uint
	46	ospf_hello3_options(struct ospf_packet *pkt)
	47	{
	48	struct ospf_hello3_packet ps = (void ) pkt;
	49	return ntohl(ps->options) & 0x00FFFFFF;
	50	}
	51
a190e720	52	void
70945cb6	53	ospf_send_hello(struct ospf_iface ifa, int kind, struct ospf_neighbor dirn)
4364b47e	54	{
70945cb6 OZ	55	struct ospf_proto *p = ifa->oa->po;
70945cb6 OZ	56	struct ospf_packet *pkt;
98ac6176	57	struct ospf_neighbor neigh, n1;
98ac6176	58	struct nbma_node *nb;
70945cb6 OZ	59	u32 *neighbors;
	60	uint length;
	61	int i, max;
86c84d76	62
391931d4	63	if (ifa->state <= OSPF_IS_LOOP)
98ac6176 OF	64	return;
98ac6176 OF	65
77539c44	66	if (ifa->stub)
70945cb6	67	return;
e3bc10fd	68
4364b47e	69
e7b76b97	70	pkt = ospf_tx_buffer(ifa);
3e2bd0f1	71	ospf_pkt_fill_hdr(ifa, pkt, HELLO_P);
e5b5d18c	72
70945cb6 OZ	73	if (ospf_is_v2(p))
	74	{
	75	struct ospf_hello2_packet ps = (void ) pkt;
	76
	77	if ((ifa->type == OSPF_IT_VLINK) \|\|
	78	((ifa->type == OSPF_IT_PTP) && !ifa->ptp_netmask))
	79	ps->netmask = 0;
	80	else
d44e686e	81	ps->netmask = htonl(u32_mkmask(ifa->addr->prefix.pxlen));
70945cb6 OZ	82
70945cb6 OZ	83	ps->helloint = ntohs(ifa->helloint);
1aec7112	84	ps->options = ifa->oa->options & HELLO2_OPT_MASK;
70945cb6 OZ	85	ps->priority = ifa->priority;
	86	ps->deadint = htonl(ifa->deadint);
	87	ps->dr = htonl(ipa_to_u32(ifa->drip));
	88	ps->bdr = htonl(ipa_to_u32(ifa->bdrip));
	89
	90	length = sizeof(struct ospf_hello2_packet);
	91	neighbors = ps->neighbors;
	92	}
	93	else
	94	{
	95	struct ospf_hello3_packet ps = (void ) pkt;
4727d1db	96	u32 options = ifa->oa->options \| (ifa->autype == OSPF_AUTH_CRYPT ? OPT_AT : 0);
70945cb6 OZ	97
70945cb6 OZ	98	ps->iface_id = htonl(ifa->iface_id);
1aec7112	99	ps->options = ntohl((options & HELLO3_OPT_MASK) \| (ifa->priority << 24));
70945cb6 OZ	100	ps->helloint = ntohs(ifa->helloint);
	101	ps->deadint = htons(ifa->deadint);
	102	ps->dr = htonl(ifa->drid);
	103	ps->bdr = htonl(ifa->bdrid);
	104
	105	length = sizeof(struct ospf_hello3_packet);
	106	neighbors = ps->neighbors;
	107	}
e5b5d18c	108
77539c44	109	i = 0;
70945cb6	110	max = (ospf_pkt_maxsize(ifa) - length) / sizeof(u32);
8e48831a	111
70945cb6	112	/* Fill all neighbors */
8e48831a	113	if (kind != OHS_SHUTDOWN)
e5b5d18c	114	{
8e48831a	115	WALK_LIST(neigh, ifa->neigh_list)
3e2bd0f1	116	{
70945cb6	117	if (i == max)
8e48831a	118	{
f8fefde3	119	log(L_WARN "%s: Too many neighbors on %s", p->p.name, ifa->ifname);
8e48831a OZ	120	break;
8e48831a OZ	121	}
70945cb6	122	neighbors[i] = htonl(neigh->rid);
8e48831a	123	i++;
3e2bd0f1	124	}
e5b5d18c OF	125	}
e5b5d18c OF	126
70945cb6 OZ	127	length += i * sizeof(u32);
	128	pkt->length = htons(length);
	129
	130	OSPF_TRACE(D_PACKETS, "HELLO packet sent via %s", ifa->ifname);
e5b5d18c	131
98ac6176	132	switch(ifa->type)
e5b5d18c	133	{
919f5411 OZ	134	case OSPF_IT_BCAST:
919f5411 OZ	135	case OSPF_IT_PTP:
95127cbb	136	ospf_send_to_all(ifa);
919f5411 OZ	137	break;
	138
	139	case OSPF_IT_NBMA:
beeda6af	140	if (dirn) /* Response to received hello */
919f5411 OZ	141	{
919f5411 OZ	142	ospf_send_to(ifa, dirn->ip);
98ac6176	143	break;
919f5411 OZ	144	}
	145
	146	int to_all = ifa->state > OSPF_IS_DROTHER;
	147	int me_elig = ifa->priority > 0;
742029eb	148
8e48831a	149	if (kind == OHS_POLL) /* Poll timer */
919f5411 OZ	150	{
	151	WALK_LIST(nb, ifa->nbma_list)
	152	if (!nb->found && (to_all \|\| (me_elig && nb->eligible)))
	153	ospf_send_to(ifa, nb->ip);
	154	}
	155	else /* Hello timer */
	156	{
	157	WALK_LIST(n1, ifa->neigh_list)
	158	if (to_all \|\| (me_elig && (n1->priority > 0)) \|\|
	159	(n1->rid == ifa->drid) \|\| (n1->rid == ifa->bdrid))
	160	ospf_send_to(ifa, n1->ip);
	161	}
	162	break;
	163
	164	case OSPF_IT_PTMP:
	165	WALK_LIST(n1, ifa->neigh_list)
	166	ospf_send_to(ifa, n1->ip);
	167
	168	WALK_LIST(nb, ifa->nbma_list)
	169	if (!nb->found)
	170	ospf_send_to(ifa, nb->ip);
	171
	172	/* If there is no other target, we also send HELLO packet to the other end */
	173	if (ipa_nonzero(ifa->addr->opposite) && !ifa->strictnbma &&
	174	EMPTY_LIST(ifa->neigh_list) && EMPTY_LIST(ifa->nbma_list))
	175	ospf_send_to(ifa, ifa->addr->opposite);
	176	break;
	177
	178	case OSPF_IT_VLINK:
	179	ospf_send_to(ifa, ifa->vip);
	180	break;
	181
	182	default:
70945cb6	183	bug("Bug in ospf_send_hello()");
e5b5d18c	184	}
70945cb6	185	}
8298d780	186
70945cb6 OZ	187
	188	void
	189	ospf_receive_hello(struct ospf_packet pkt, struct ospf_iface ifa,
	190	struct ospf_neighbor *n, ip_addr faddr)
	191	{
	192	struct ospf_proto *p = ifa->oa->po;
f8fefde3	193	const char *err_dsc = NULL;
70945cb6	194	u32 rcv_iface_id, rcv_helloint, rcv_deadint, rcv_dr, rcv_bdr;
d3f4f92b OZ	195	uint rcv_options, rcv_priority;
d3f4f92b OZ	196	uint loc_options = ifa->oa->options;
70945cb6 OZ	197	u32 *neighbors;
70945cb6 OZ	198	u32 neigh_count;
f8fefde3	199	uint plen, i, err_val = 0;
70945cb6 OZ	200
	201	/* RFC 2328 10.5 */
	202
f8fefde3	203	/*
d44e686e	204	* We may not yet have the associate neighbor, so we use Router ID from the
f8fefde3 OZ	205	* packet instead of one from the neighbor structure for log messages.
	206	*/
	207	u32 rcv_rid = ntohl(pkt->routerid);
	208	OSPF_TRACE(D_PACKETS, "HELLO packet received from nbr %R on %s", rcv_rid, ifa->ifname);
70945cb6 OZ	209
	210	plen = ntohs(pkt->length);
	211
	212	if (ospf_is_v2(p))
	213	{
	214	struct ospf_hello2_packet ps = (void ) pkt;
	215
	216	if (plen < sizeof(struct ospf_hello2_packet))
f8fefde3	217	DROP("too short", plen);
70945cb6 OZ	218
	219	rcv_iface_id = 0;
	220	rcv_helloint = ntohs(ps->helloint);
	221	rcv_deadint = ntohl(ps->deadint);
	222	rcv_dr = ntohl(ps->dr);
	223	rcv_bdr = ntohl(ps->bdr);
	224	rcv_options = ps->options;
	225	rcv_priority = ps->priority;
	226
	227	int pxlen = u32_masklen(ntohl(ps->netmask));
3e236955 JMM	228	if (pxlen < 0)
	229	DROP("prefix garbled", ntohl(ps->netmask));
	230
70945cb6 OZ	231	if ((ifa->type != OSPF_IT_VLINK) &&
70945cb6 OZ	232	(ifa->type != OSPF_IT_PTP) &&
8860e991	233	((uint) pxlen != ifa->addr->prefix.pxlen))
f8fefde3	234	DROP("prefix length mismatch", pxlen);
70945cb6 OZ	235
	236	neighbors = ps->neighbors;
	237	neigh_count = (plen - sizeof(struct ospf_hello2_packet)) / sizeof(u32);
	238	}
	239	else /* OSPFv3 */
	240	{
	241	struct ospf_hello3_packet ps = (void ) pkt;
	242
	243	if (plen < sizeof(struct ospf_hello3_packet))
f8fefde3	244	DROP("too short", plen);
70945cb6 OZ	245
	246	rcv_iface_id = ntohl(ps->iface_id);
	247	rcv_helloint = ntohs(ps->helloint);
	248	rcv_deadint = ntohs(ps->deadint);
	249	rcv_dr = ntohl(ps->dr);
	250	rcv_bdr = ntohl(ps->bdr);
d3f4f92b OZ	251	rcv_options = ntohl(ps->options) & 0x00FFFFFF;
d3f4f92b OZ	252	rcv_priority = ntohl(ps->options) >> 24;
70945cb6 OZ	253
	254	neighbors = ps->neighbors;
	255	neigh_count = (plen - sizeof(struct ospf_hello3_packet)) / sizeof(u32);
	256	}
	257
	258	if (rcv_helloint != ifa->helloint)
f8fefde3	259	DROP("hello interval mismatch", rcv_helloint);
70945cb6 OZ	260
70945cb6 OZ	261	if (rcv_deadint != ifa->deadint)
f8fefde3	262	DROP("dead interval mismatch", rcv_deadint);
70945cb6 OZ	263
70945cb6 OZ	264	/* Check whether bits E, N match */
d3f4f92b	265	if ((rcv_options ^ loc_options) & (OPT_E \| OPT_N))
f8fefde3	266	DROP("area type mismatch", rcv_options);
70945cb6	267
d3f4f92b OZ	268	/* RFC 5838 2.4 - AF-bit check unless on IPv6 unicast */
	269	if ((loc_options & OPT_AF) && !(loc_options & OPT_V6) && !(rcv_options & OPT_AF))
	270	DROP("AF-bit mismatch", rcv_options);
	271
70945cb6 OZ	272	/* Check consistency of existing neighbor entry */
	273	if (n)
	274	{
a7a7372a	275	uint t = ifa->type;
70945cb6 OZ	276	if (ospf_is_v2(p) && ((t == OSPF_IT_BCAST) \|\| (t == OSPF_IT_NBMA) \|\| (t == OSPF_IT_PTMP)))
	277	{
	278	/* Neighbor identified by IP address; Router ID may change */
f8fefde3	279	if (n->rid != rcv_rid)
70945cb6	280	{
f8fefde3 OZ	281	OSPF_TRACE(D_EVENTS, "Neighbor %R on %s changed Router ID to %R",
	282	n->rid, ifa->ifname, rcv_rid);
	283	ospf_neigh_sm(n, INM_KILLNBR);
70945cb6 OZ	284	n = NULL;
	285	}
	286	}
	287	else /* OSPFv3 or OSPFv2/PtP */
	288	{
	289	/* Neighbor identified by Router ID; IP address may change */
	290	if (!ipa_equal(faddr, n->ip))
	291	{
f8fefde3	292	OSPF_TRACE(D_EVENTS, "Neighbor %R on %s changed IP address to %I",
0ac9cb2c	293	n->rid, ifa->ifname, faddr);
70945cb6 OZ	294	n->ip = faddr;
	295	}
	296	}
	297	}
	298
	299	if (!n)
	300	{
	301	if ((ifa->type == OSPF_IT_NBMA) \|\| (ifa->type == OSPF_IT_PTMP))
	302	{
	303	struct nbma_node *nn = find_nbma_node(ifa, faddr);
	304
	305	if (!nn && ifa->strictnbma)
f8fefde3	306	DROP1("new neighbor denied");
70945cb6 OZ	307
	308	if (nn && (ifa->type == OSPF_IT_NBMA) &&
	309	(((rcv_priority == 0) && nn->eligible) \|\|
	310	((rcv_priority > 0) && !nn->eligible)))
f8fefde3	311	DROP("eligibility mismatch", rcv_priority);
70945cb6 OZ	312
	313	if (nn)
	314	nn->found = 1;
	315	}
	316
6f8bbaa1 OZ	317	OSPF_TRACE(D_EVENTS, "New neighbor %R on %s, IP address %I",
6f8bbaa1 OZ	318	rcv_rid, ifa->ifname, faddr);
70945cb6 OZ	319
	320	n = ospf_neighbor_new(ifa);
	321
f8fefde3	322	n->rid = rcv_rid;
70945cb6 OZ	323	n->ip = faddr;
	324	n->dr = rcv_dr;
	325	n->bdr = rcv_bdr;
	326	n->priority = rcv_priority;
	327	n->iface_id = rcv_iface_id;
	328
	329	if (n->ifa->cf->bfd)
	330	ospf_neigh_update_bfd(n, n->ifa->bfd);
	331	}
	332
	333	u32 n_id = ospf_is_v2(p) ? ipa_to_u32(n->ip) : n->rid;
	334
	335	u32 old_dr = n->dr;
	336	u32 old_bdr = n->bdr;
	337	u32 old_priority = n->priority;
	338	u32 old_iface_id = n->iface_id;
	339
	340	n->dr = rcv_dr;
	341	n->bdr = rcv_bdr;
	342	n->priority = rcv_priority;
	343	n->iface_id = rcv_iface_id;
	344
70945cb6 OZ	345	/* Update inactivity timer */
	346	ospf_neigh_sm(n, INM_HELLOREC);
	347
	348	/* RFC 2328 9.5.1 - non-eligible routers reply to hello on NBMA nets */
	349	if (ifa->type == OSPF_IT_NBMA)
	350	if ((ifa->priority == 0) && (n->priority > 0))
	351	ospf_send_hello(n->ifa, OHS_HELLO, n);
742029eb	352
70945cb6 OZ	353
	354	/* Examine list of neighbors */
	355	for (i = 0; i < neigh_count; i++)
	356	if (neighbors[i] == htonl(p->router_id))
	357	goto found_self;
	358
	359	ospf_neigh_sm(n, INM_1WAYREC);
	360	return;
	361
f8fefde3	362	found_self:
70945cb6 OZ	363	ospf_neigh_sm(n, INM_2WAYREC);
	364
	365
	366	if (n->iface_id != old_iface_id)
	367	{
	368	/* If neighbor is DR, also update cached DR interface ID */
	369	if (ifa->drid == n->rid)
	370	ifa->dr_iface_id = n->iface_id;
	371
	372	/* RFC 5340 4.4.3 Event 4 - change of neighbor's interface ID */
	373	ospf_notify_rt_lsa(ifa->oa);
	374
	375	/* Missed in RFC 5340 4.4.3 Event 4 - (Px-)Net-LSA uses iface_id to ref Link-LSAs */
	376	ospf_notify_net_lsa(ifa);
	377	}
	378
	379	if (ifa->state == OSPF_IS_WAITING)
	380	{
	381	/* Neighbor is declaring itself DR (and there is no BDR) or as BDR */
	382	if (((n->dr == n_id) && (n->bdr == 0)) \|\| (n->bdr == n_id))
	383	ospf_iface_sm(ifa, ISM_BACKS);
	384	}
	385	else if (ifa->state >= OSPF_IS_DROTHER)
	386	{
	387	/* Neighbor changed priority or started/stopped declaring itself as DR/BDR */
	388	if ((n->priority != old_priority) \|\|
	389	((n->dr == n_id) && (old_dr != n_id)) \|\|
	390	((n->dr != n_id) && (old_dr == n_id)) \|\|
	391	((n->bdr == n_id) && (old_bdr != n_id)) \|\|
	392	((n->bdr != n_id) && (old_bdr == n_id)))
	393	ospf_iface_sm(ifa, ISM_NEICH);
	394	}
f8fefde3 OZ	395
	396	return;
	397
	398	drop:
	399	LOG_PKT("Bad HELLO packet from nbr %R on %s - %s (%u)",
	400	rcv_rid, ifa->ifname, err_dsc, err_val);
4364b47e	401	}